Poker vibrators are used for internally vibrating elastic materials such as freshly poured concrete and include an eccentric weight arranged to rotate in a cylindrical casing. The vibration-generating rotational motion of the weight is imparted to the latter either by an external drive unit or by an electric motor incorporated in the poker.
Poker vibrators of the kind referred to above are generally classified as hand tools in which power is transmitted from the power source or drive unit to the eccentric weight arranged inside the cylindrical casing of the poker via an electric cable, a flexible drive shaft or a compressed air hose. For practical reasons connected with the way the poker is used, the sheathing enclosing the cable, drive shaft, et cetera, is relatively stiff, at least that part of it closest to the poker held by the operator is, with the result that a large proportion of the vibration generated in the poker is also transmitted to this part of the sheathing. The propagated vibration is often of such a magnitude that it can harm the operator, particularly over long periods of time.